IT seemed to me by the end of last week that Darryl Littlejohn was either too damn lucky – or an innocent man.

Now, he appears just lucky.

Even that’s about to change.

An agonizing 2 ½ weeks after lovely Imette St. Guillen was found tortured, raped, murdered and dumped in Brooklyn, the police commissioner has named Littlejohn the prime suspect in the vicious crime that has riveted this city.

Ray Kelly spoke those words yesterday with some relief. For too long, it appeared that Littlejohn, a maddeningly cool and startlingly dumb ex-con, was actually some kind of criminal mastermind.

Now, it simply appears Littlejohn had help. The only question is – How much help?

Danny Dorrian, a co-owner of The Falls bar where Littlejohn worked, allegedly lied to cops for an entire week about what happened the night Imette disappeared. He’d ordered Littlejohn to get the drunken grad student out of his bar, but did not want the cops to know. This would have given Littlejohn an opportunity to cover his tracks.

It appears he almost did.

For a week, it seemed he’d left not a trace of himself on or around the victim. He was hauled before victims of two previous rapes, but those women failed to pick Littlejohn out of police lineups.

Littlejohn seized the opportunity to rail against our justice system, saying he was the victim of a racist conspiracy. He made our cops look like chumps.

Maybe he didn’t do it. Even I was starting to have my doubts.

When cops hauled Littlejohn into the 112th Precinct station house in Queens last week, they hoped a rape victim would pick him out of another lineup. She didn’t.

Suddenly – and I don’t say this easily – Littlejohn looked like he was being railroaded.

But evidently, the dumb ex-con didn’t have time to cover every track. His blood has been definitively matched to that found on the plastic restraints binding poor Imette’s wrists. It’s a “one in a trillion” chance, said Kelly, that blood came from anyone else.